Background: Afterschool programs (ASPs) in the United States have been implemented in low income neighborhoods to enable at-risk youth to access educational support services to increase academic skills. However, mixed findings about the ASPs positively affecting academic performance suggests a need for additional evaluative studies. Objective: The current study examines the effects of literacy training on the reading skills of kindergarten to third grade students who were enrolled in a community-based ASP in four public housing neighborhoods. Participants received structured literacy and reading training, individual tutoring, and a choice-based book distribution program. Method: Assignment to treatment and comparison groups was based on residence in public housing neighborhoods. We implemented a quasi-experimental design to compare improvements in reading proficiency among ASP literacy program participants in four public housing neighborhoods and a comparable group of students residing in two other public housing neighborhoods without this ASP. Participants were enrolled in grades K to 3 (n = 543). The study lasted for 4 years, and an intent-to-treat approach was used to analyze outcomes. Mixed-effects models indicated that among a full sample and propensity-score matched sample, ASP participants demonstrated significantly better reading proficiency than comparison group participants over time. Conclusions: Study findings provide preliminary evidence that it is possible to impact reading proficiency for very high-risk students in the early grades of elementary school. ASPs that target literacy among low-income students could play an important role in boosting student achievement, and therefore in narrowing the achievement gap as young people progress through school.